Process of imparting drying properties to varnishes.



, 5 r are usually either first heated with theoil at.

" v U D STATES PATENT OFFICE.

Y AUGUST P. BJERREGAARD, F YORK, N. Y., ASSIGNOR TO CHARLES W. COOPER,OF SAME PLACE. v

PROCESS OF I'MPARYTIVNG DRYING PROPERTIES TO VARNlSHESi I srncrrrcn'rronforming art of Letters Patent No. 629,330, dated July 25, 1899-. 7Application filed July 21, 1898. Serial No. 686,488. (No specimens.)

To all whom it mcty cancer-m Be it known that I, AUGUST P. B JERREGAARD, a citizen of the United States, residing at New York city, Stateof New York, have invented certain new and useful Improvements.

in Processes for Impartin g Drying Properties My invention relates to amethod of treating varnishes (made of copal-gum, fatty dryingso'il, anda thinning agent) with other sub stances Which'shall cause the same to r-zceive additional drying properties. 7

In processes of making gum and fatty-oil varnishesheretofore employedthedriers used a high temperature before the oil is added to thegum or thedriers are boiled simultaneously with the oil and the gum, an operationrequiring high temperature. In the manufacture of certain varnishes itis preferable to use oil which has not been previously boiled,

because a varnish made of such unboiled oil is more lasting than oneinwhich previouslyboiled oil is used, and therefore anytreatobjectionable, and it hasbeen my experience that when the drier isboiled .with the oil or with both the gum and the oil the results are e7 Therefore the ability to make a good dryingbeen completed by theincorporation by heat of the gum with the oil, after they have beenvarnish with the use of a large proportion of unboiled oil is anadvantage.

'I have found that by my process drying properties can beadded tovarnishes made of fatty drying-oil and copal after the same have thinnedwith a suitable agent, and preferably after they have becomecomparatively or entirely cool. I may also by my process add an excessof drying properties to varnishes made of fatty drying-oil and copal,and thereby fit them for use as driers for other kindred varnishes.

In the preferred manner of carryingout process I add to the previouslyboiled and cooled varnish (after thinning it with a suit able agent andwhen said varnish is at any temperature below the boiling-point of thesaid agent, and preferably at ordinary atmos.

pheric temperature) a small quantityof an oxid of a metal, preferablythe'oxid of lead,

known as litharge say aboutone-tenthof one per cent, thereof, more orless. 4 I also add borate of manganese, sulfate of m'anganese, or othersuitable manganese salt in alent for each chemical equivalent of thelead oxid used. I then suitably agitate the mixture until the dryingproperty of the varnish is The lead oxid, together with the manganesesalt, may be added together to the varnish, or either may be added firstand the other afterward. While it is preferable to use the lead oxid andthe manganese salt in equal molecular proportionsfor example, in theratio of two hundred and nineteen pounds oxid pf lead to one hundred andninety-five pounds commercial precipitated borate of manganeseI find itis not absolutely neces- I sary to observe these exact proportions, forif, for instance, an excess of lead oxid is used it Will remain insolution in the finished varnish with little,if any,detrimental efiectupon it if the excess is not too great, While if an excess of themanganese salt is used it will sim-' a y P ably about one chemicalequivply remain undissolved to be subsequently settled or filtered out,together with the insoluble lead salt formed by chemical reactionduring'the operation. I prefer, however, to avoid using an excess oflead, and in order to prevent any lead remaining in the finished varnishI oftenuse an excess of manganese salt. The amount of lead oxid andmanganese salt required in any particular case depends on the kind ofvarnish operated upon and also upon'the drying quality desired in theproduct; The quicker the product is desired to dry the greater must bethe proportion of the drying agents. If the product turns: out aftertreatment by this process to dry too fast, the drying property may bereduced by adding a suitable quantity of untreated varnish. If, on theother hand, it does not dry fast enough, more lead oxid and manganesesalt may be added, or there may be added to the product enough of verystrongly-drying varnish to give the desired drying quality to the whole.

Apparently the chemical changes involved in this process consist, in thefirst place, of a combination between the oxid of lead and the varnish,or one or more of its constituents, and then, in the second place, of adouble decomposition between the so-formed lead compound and themanganese salt, resulting in the formation of acompound of manganeseoxid and the varnish, or one or more of its constituents, and of a saltof lead insoluble in the varnishas, for example, lead borate whenmanganese borate is used.

I have made a number of tests to determine the proportions of driers insome of the bestknown varnishes on the market, and in all that I havetested I have found the proportions of such driers to be much greaterthan is required by my process to produce equal drying effects, and asthe smaller the quantity of drier in the finished product the morelasting is the varnish the smaller amountof drier required by my processconstitutes an advantage consisting partly in the improvement in thequality of the varnish and partly in a saving in the cost of thechemicals used.

As an illustrative example of how I may carry out my process 'inpractical operations the following directions are given: Assuming it isdesired to treat an outside body-varnish made (for example, by theprocess described in my pending application for Letters Patent, SerialNo. 644,009, filed July 9, 1897) of kauri, raw linseed-oil, andturpentine in the proportions of sixty poundsof the copal, fifteengallons of the oil, and twenty-two gallons of the thinning agent, Itake, say, one hundred gallons of this varnish and place it in a closedtank fitted with a suitable stirring arrangement. I then add six ouncesof lith arge and six ounces of commercial borate of manganese and stirthe mass for about three or four hours. During the stirring or agitationit is well to provide against such-currents of air as would cause awasteful loss of the thinning agent by evaporation. After this treatmentthe resulting product will resemble the varnish before being operatedupon in all particulars except in its drying properties. Beforetreatment it might have dried"dust free in, say, four or five days,whereas after the treatment above described it maydry in ten hours orless.

While this process is applicable to varnishes made with copal and afatty oil other than a drying-oil and a thinning agent, the same is notmade the subject-matter of this application, but is made thesubject-matter of another application filed by me, which is a divisionhereof.

What I claim is- 1. The process'of treating a varnish made of copal,fatty drying-oil, and thinning agent, so as to add drying propertiesthereto, consisting in mixing with the said varnish, at a temperaturenot above the boiling-point of the thinning agent, driers consisting ofan oxid of a suitable metal and a'suitable manganese salt, said driersbeing substantially in the relative proportions set forth; the totalweight of driers remaining in solution being less than one-third of oneper cent.

2. The process of treating a varnish made of copal, fatty drying-oil,and thinning agent, so as to add drying properties thereto, consistingin mixing with the said varnish, at a temperature not above theboiling-point of the thinning agent, driers consisting of oxid of lead,and a suitable manganese salt, said driers being substantially inthe'relative proportions set forth; the total weight of driers remainingin solution being less than onethird of one per cent.

. Signed at New York, N. Y., this 15th day of July, 1898.

AUGUST P. BJERREGAARD.

Witnesses:

EMERSON R. NEWELL, L. VREELAND.

